A similar battery unit is, for example, described in DE 10 2008 016 936 A2. There, the edges of the metal cooling sheets are bent at 90 degrees in order to cover the cells in a form-fitting way and to thereby provide a connection to a heat sink.
Battery units of this type can create levels of pressure inside the cells through overheating, short circuits, or other electrical incidents that cause the cells to burst and subsequently leak the gas that was created in the cells. This process can even lead to the formation of flames. If the flames spread to an adjacent cell, that cell may also overheat, resulting in a chain reaction that can pose a serious safety risk.